Frequency diffuser



FIG. 1 is a front perspective view of a frequency diffuser showing ournew design.

FIG. 2 is a back perspective view thereof.

FIG. 3 is a top view thereof.

FIG. 4 is a front view thereof.

FIG. 5 is a side view thereof; and,

FIG. 6 is a back view thereof.

The design is for a Quadratic Residue Diffuser (QRD) acoustic diffuserwhich is used to control reflection of sound in a listening environment.

CLAIM The ornamental design for a frequency diffuser, as shown anddescribed.